Occupational exposure at petrol stations and red- green colour vision deficiency: a case-control study from Sudan.

Balanced spatiotemporal color responses are fine-tuned to natural light spectrum in mice ventral retina.

Introduction This study documents the results of the rehabilitation services offered to 1136 persons with vision impairment in Jordan over the period 2012–2020. Information is presented about the causes of visual impairment, functional vision assessment, offered rehabilitation services, functional problems and needs, and recommended low vision devices. Methods A retrospective file study was carried out on data of 1136 service users (538 children, 598 adults). The data was classified and analyzed to give descriptive statistics including main cause of low vision; service users’ priorities; visual functions (distance and near visual acuity, reading acuity, contrast sensitivity, peripheral visual field, and color vision); and prescribed low vision devices. Results Just under half of service users (n = 498, 43.8%) had moderate visual impairment (0.3 > Visual Acuity ≥ 0.1). Only 8.5% of the files represented individuals who had a binocular visual field of less than 20 degrees in either the vertical or horizontal planes. Near tasks (writing, reading, technology use, and work-related tasks) were reported as the first priority by the majority of the service users (78.9%). Retinal diseases represented the cause of half of low vision cases (n = 568, 50.0%), followed by albinism (n = 83, 7.3%). Among the 1078 assistive low vision devices that were prescribed (first and second choices), near-field devices were prescribed as a first choice (58.01%), then distance devices (12.32%). Discussion The findings indicate that retinal diseases are the dominant cause of low vision in this population, the majority of whom needed remediation for near tasks. Implications for Practitioners Comprehensive assessment of visual functions that includes visual acuity, reading acuity, visual field, contrast sensitivity, and color vision is essential to provide better rehabilitation and to recommend proper low vision devices. The study reveals to decision makers the importance of planning and developing low vision services.

Purpose To examine the association between female color vision deficiency (CVD) and other ophthalmic disorders including amblyopia and strabismus. Methods A retrospective, cross-sectional analysis of female adolescents undergoing military medical assessments between the years 2000 and 2020 was conducted. The prevalence of ophthalmic conditions, such as amblyopia, strabismus, and ametropia, was examined in both females with CVD and those with normal color vision. Demographic and socioeconomic data were also collected and analyzed. Results 912 females with CVD (mean age 17.1 ± 0.2 years) were identified within a cohort of 621,471 Israeli army female recruits. Female adolescents with CVD had higher prevalence of amblyopia (4.61% vs 0.66%, p < 0.001), strabismus (2.96% vs 0.81%, p < 0.001), and ametropia (moderate – less than 6.00 diopters, 40.46% vs 37.48%, p < 0.001, and high – higher than 6.00 diopters, 4.50% vs 1.95% p < 0.001) compared to females with normal color vision. Specific refractive data was available for a subgroup of 256 CVD females, demonstrating higher prevalence of both mild to moderate hyperopia (up to +6.00 diopters, 7.36% vs 2.72%, p < 0.001) and high hyperopia (≥ +6.00 diopters, 1.16% vs 0.13%, p < 0.001), but not for myopia or astigmatism. Conclusions CVD in young females is strongly associated with strabismus, hyperopia and amblyopia, suggesting that early population screening for CVD at a young age could identify girls at a higher risk for preventable vision loss.

Rapid test for detecting red-green color vision deficiencies using a neural network-assisted color-naming task.

Investigating ethnicity-related variability in the human L-cone spectral sensitivity function.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a rare autoimmune disease affecting the central nervous system, frequently manifesting with optic neuritis (ON). Despite often favourable functional visual recovery, structural retinal changes may persist. This prospective study assessed the utility of functional and structural visual outcome measures in paediatric MOGAD. Children with serologically confirmed MOGAD were recruited from across Switzerland, alongside age-matched healthy controls. All participants underwent pattern-reversal visual evoked potentials (VEP; 15' and 60' check sizes), spectral-domain optical coherence tomography (OCT), high- and low-contrast distance visual acuity (VA), near VA, and colour vision testing. VEP outcomes were P100 peak times, and OCT outcomes were peripapillary retinal nerve fibre layer (pRNFL) thickness (global, temporal, nasal, and papillomacular bundle (PMB)), macular volume, and central retinal thickness. Discriminative performance was assessed using receiver operating characteristic (ROC) analysis. Twelve paediatric MOGAD patients (10.9 ± 3.1years) and twelve age-matched controls (11.5 ± 2.8years) were included. VEP P100 peak times were generally comparable between patients and controls. pRNFL thickness appeared lower in patients than controls. ROC analysis showed excellent to outstanding discrimination for global, PMB, temporal, and nasal pRNFL sectors, both overall and in ON+ and ON- subgroups. VEP P100 peak times exhibited fair or poor discrimination overall, however 15' check sizes showed excellent discrimination between ON+ and control eyes. In our cohort, OCT-derived pRNFL thickness differentiated MOGAD from controls with high accuracy, including in eyes without prior ON. VEPs showed limited utility, supporting OCT as a more sensitive marker of subclinical structural involvement.

This study aimed to compare the AI-assisted Virtual Reality Platform (VRP) with technician-assisted exams for assessing visual acuity, color vision (CV), and visual field (VF) in a neuro-ophthalmology clinic. A comparative, cross-sectional study including 59 adult patients was performed in the neuro-ophthalmology clinic at Bascom Palmer Eye Institute. The Snellen chart for visual acuity, Ishihara testing, and the SITA or AVA Fast strategy for VF testing were used in both the VRP and technician-based examinations. Best corrected visual acuity (BCVA), CV results, mean deviation (MD), pattern standard deviation (PSD), and reliability indices were collected. The study included 118 eyes with a mean age of 47.2 ± 18.8 (71.19% female). Significant positive correlations were found between the VRP and technician-based examination for BCVA (r = .641, P<.001) and CV (r = .824, P<.001). Bland-Altman analysis showed good agreement between VRP and the traditional exams for BCVA (mean bias 0.09 ± 0.25, limits of agreement (LOA): [0.58] to [-0.40]) and CV (mean bias 0.07 ± 0.11. LOA: [0.29] to [-0.16]). The MD and PSD of the VRP were significantly correlated with the standard Humphrey Visual Field (HVF) exam (MD: r = .91, P<.001; PSD: r = .88, P<.001). Bland-Altman analysis revealed a mean bias of -0.71 ± 2.81 for MD and - 0.90 ± 2.08 for PSD. The VRP reduced test duration (124.31 ± 0.35s) compared to the standard exam (256.8 ± 7.1s, P<.0001). The VisuALL VRP, a compact portable device, effectively provides results comparable to technician-based assessments in neuro-ophthalmological patients while reducing test duration and improving clinical workflow.

A hallmark of the IMPDH1-related rod-cone dystrophy is the highly variable expressivity. Disease onset, severity and progression are variant-dependent due to specific affected photoreceptor mechanisms, underscoring the importance of genotype-phenotype correlations. We provide a detailed clinical characterization of a patient with rod-cone dystrophy caused by a rare de novo missense IMPDH1 variant. A 33-year-old female patient was assessed over a period of four years following the onset of her symptoms. A multimodal evaluation of both structural and functional aspects, along with molecular analysis, was performed. We identified a rare de novo missense variant in the IMPDH1 gene (NM_000883.4:c.730A > C, p.Thr244Pro), which had been previously reported in one patient. Threonine 244 is located at the interface between the catalytic domain and the regulatory Bateman domain. This region is crucial for GDP/GTP nucleotide binding and mediates feedback regulation, putatively influencing allosteric regulation. The SD-OCT imaging revealed a symmetrically preserved ellipsoid zone in the central retina, alongside noticeable neuroretinal layer loss beyond the temporal vascular arcades. Functional examinations showed normal BCVA, microperimetric macular thresholds, and color vision thresholds in both eyes. Multifocal ERG was slightly reduced, and full-field ERGs were affected in both dark- and light-adapted responses, consistent with the peripheral sensitivity loss in the 80° automated visual field. No significant changes were observed throughout the follow-up period. The IMPDH1 p.Thr244Pro variant was associated with preserved central retina structure and function with stable peripheral dysfunction in the fourth decade of life, suggesting a relatively stationary disease course that starkly contrasts the rapid progression of retinal dystrophies caused by other IMPDH1 variants.

ABSTRACT Color vision is essential for human perception, yet red‐green color vision deficiency (CVD) affects millions and poses significant challenges for chromatic discrimination. Existing assistive technologies are often static and distort true color perception. In this study, we introduce a novel photo‐synaptic device designed to enhance chromatic discrimination for individuals with red‐green CVD by converting photonic signals into digital synaptic currents. Utilizing a poly(3‐hexylthiophene) (P3HT)‐based organic heterojunction, our device achieves a tenfold improvement in wavelength discrimination between red and green light compared to a control device that mimics red‐green color blindness. When integrated with artificial neural networks, the device demonstrates a remarkable 92% accuracy in recognizing complex chromatic patterns. Our findings further demonstrate the device's potential to enhance color recognition for individuals with color weakness, enabling more effective differentiation of intricate patterns. This work provides a robust solution for enhancing color perception and lays the groundwork for next‐generation bioelectronic systems focused on sensory restoration.

Background/Objectives: Visual dysfunction is a common non-motor symptom in Parkinson's Disease (PD), as evidenced by deficits in color vision (CV) and binocular vision (BV). Computerized CV tests, such as the Cambridge Color Test (CCT), are underutilized in this patient population despite the known limitations of common CV tests. Methods: In total, 19 PD and 12 control participants underwent a comprehensive eye exam, including ocular motility testing and the CCT, utilizing thresholds obtained along 12 contrast vectors to fit a discrimination ellipse. Findings were compared across groups, and the association with disease severity was analyzed. Results: PD participants showed increases in ellipse area (p = 0.012) and short-axis length (p = 0.009). PD participants demonstrated convergence insufficiency type exotropia (p < 0.001) and impaired stereopsis (p = 0.006). No significant correlation with UPDRS scores was seen for either BV or CV. Conclusions: PD participants exhibited binocular vision dysfunction with selective changes in color vision. CV changes are more variable in PD, likely due to mixed parvocellular and cortical dysfunction. Convergence insufficiency type exotropia is more common in PD, likely due to combined cortical and subcortical neurodegeneration. Both BV and CV changes occur independently of motor severity, emphasizing the need for routine visual testing regardless of symptom progression.

The swallowtail butterfly Papilio xuthus is a model species in insect vision science, thanks to extensive studies over the past few decades. P. xuthus adaptively uses visual cues such as color, brightness, polarization and motion in various steps of flower-foraging behavior. We have explored these visual functions from both perceptual and physiological perspectives. This Review aims to summarize these studies by focusing on color vision as a prominent ability in foraging P. xuthus and on wide-field motion vision as a more-universal visual modality in insects. The compound eyes of P. xuthus consist of three types of ommatidia, each with a different combination of spectral receptor classes: sensitive to ultraviolet (UV), violet (V), blue (B), green (G), red (R) and broadband (BB) wavelength regions. Connectome analysis of the first optic ganglion, the lamina, reveals interphotoreceptor interaction causing spectral opponency and spectral integration in the second-order lamina monopolar cells (LMCs). These characteristics should be crucial in the initial processing underlying the acute color discrimination ability of tetrachromatic color vision based on UV, B, G and R receptors, as well as motion vision involving G, R and BB receptors. In addition, we have revealed that the spectral properties of interneurons connecting the optic lobe and the central brain well explain the behavioral properties of P. xuthus. By discussing the visual system of P. xuthus butterflies in conjunction with knowledge from honeybees, flies and other lepidopteran insects, we will provide valuable insights into the evolution of insect visual systems.

Drivers with color vision deficiency (CVD) often face difficulty recognizing traffic light colors at intersections. Relying solely on their limited color vision can increase safety risks while driving in urban environments. In the era of technological development, Intelligent Transportation Systems (ITSs) increasingly aim to provide support for traffic users, including individuals with CVD. To address user needs from diverse backgrounds, this study aims to develop a traffic light recognition system that provides offline multilingual audio feedback in Indonesian, Mandarin, and English. The proposed approach introduces a spatial-position inference framework by applying a full-frame traffic light annotation strategy to a YOLOv12 model, enabling traffic light state recognition based on the relative position of active lights rather than relying primarily on color information. This work contributes to reducing reliance on color-based perception traffic signal recognition frameworks tailored for assistive ITS applications targeting users with color vision deficiency. System performance is evaluated to verify its feasibility using a comprehensive dataset consisting of various traffic light conditions, including daytime and nighttime scenarios, varying weather, and different traffic densities. Experimental results show an average detection confidence of approximately 0.73, with a maximum confidence of 0.95 and low processing latency of 0.214 s on a CPU-only configuration. The system has the potential to enhance driving safety for individuals with color vision deficiency by offering an additional intelligent assistive tool instead of replacing standard driving regulations.

Background/Objectives: Hydroxychloroquine (HCQ) is used to manage various autoimmune diseases, including systemic lupus erythematosus. The prolonged use of HCQ is associated with retinopathy and irreversible visual loss due to retinal toxicity. Despite adherence to dosage regimens, patients may develop functional rather than structural changes, without detectable abnormalities on routine examination using visual acuity and optical coherence tomography (OCT). The study aimed to detect early signs of retinopathy in patients with autoimmune diseases treated with HCQ. Methods: This cross-sectional study included patients (n = 36) with autoimmune diseases who were treated with HCQ. The control group (n = 35) comprised healthy volunteers matched for age and sex. All participants were screened using colour vision tests (Ishihara, Konan ColourDX high definition [HD]), and retinal thickness was evaluated using OCT. Results: Our findings suggest a significant reduction in the contrast threshold of the L and M-cone photoreceptors compared with that of the control using Konan ColourDX HD. The OCT measurements revealed no statistically significant difference in retinal thickness between patients and controls; however, the contrast sensitivity test showed a significant reduction at all spatial frequencies (p < 0.0001). Conclusions: The current study suggests that the Konan ColourDX cone contrast test HD and contrast sensitivity testing may be valuable for periodic monitoring of patients receiving HCQ, potentially enabling earlier detection of toxicity. However, longitudinal studies with larger cohorts are needed to confirm these findings and to further establish the clinical value of these functional visual tests.

Influence of binocular vision, ocular dominance, and sex on color discrimination.

The fovea is a unique specialization of the primate retina and is a promising site for obtaining the first complete connectome of a human central nervous system (CNS) structure. Within the fovea, neural cells and circuits have been miniaturized and compressed during evolution to sample the visual image at highest spatial resolution and begin the neural processing that serves human form, color, and motion perception. Here we present a comprehensive analysis of a sample of human foveal retina using deep learning-based segmentation to reconstruct all cells and synaptic connections at nanoscale resolution. We classified ~3,000 cells into 51 distinct morphological types based on their structural features and connectivity patterns. Our observations reveal novel synaptic pathways absent in non-human primates, suggesting specialized circuits contribute uniquely to human trichromatic color vision. A biophysical model of the distinct connectomes made by gap junctions (electrical synapses) between short- (S) and medium-long- (ML) wavelength-sensitive cone photoreceptors, suggests chromatic interactions between S and ML cones prior to the first chemical synapse. Segmentation of retinal ganglion cells (RGCs) suggests the presence of only 11 visual pathways, with 5 high-density RGC pathways accounting for over 95% of foveal output to the brain: a dramatic contrast to the 40+ ganglion cell types recognized in mouse retina. Our connectomic analysis reveals distinctive features of human neural circuitry and demonstrates how AI-based computational approaches can advance understanding of human brain structure and function.

To emulate the human color vision system, developing artificial optoelectronic synapses with multiwavelength discrimination capability is highly desired. In this work, we propose a novel optoelectronic memristor based on a Gelatin-ZnO@Sodium copper chlorophyllin (SCC) nanocomposite film. The device exhibits distinguishable response behaviors under red (680 nm), green (540 nm), and blue (430 nm) light stimuli, which enables color image perception and memory functions. Furthermore, by integrating optical potentiation and electrical depression behaviors, we implement the functionality of color image recognition in artificial neural networks. The accuracy exceeds 97.7% after only 350 training epochs. The wavelength-dependent photoresponse can be attributed to the wide absorption range of SCC and efficient carrier separation at the ZnO/SCC interface. This work provides new insights for developing efficient, multiwavelength neuromorphic vision system.

Cataract is a leading cause of reversible visual impairment in older adults and is strongly associated with reduced quality of life and increased depressive symptoms. Although cataract surgery restores visual function, its psychological impact- particularly on depression and hopelessness-remains insufficiently explored. This prospective observational study included 71 patients undergoing standard phacoemulsification with intraocular lens implantation. Visual function, depression, and hopelessness were assessed preoperatively and at 4 and 12 weeks postoperatively using the NEI VFQ-25, Beck Depression Inventory (BDI), and Beck Hopelessness Scale (BHS). Subgroup analyses were conducted for gender, marital status, employment, socioeconomic status, and education level. Statistical analyses included paired-sample tests, repeated-measures ANOVA or Friedman tests, and Cohen's d effect size calculations. Best-corrected visual acuity improved significantly from 0.61 to 0.10 logMAR. NEI VFQ-25 subscales-particularly general vision, near and distance activities, colour vision, peripheral vision, and mental health-showed marked postoperative improvement (all p 0.001; large effect sizes). Mean BDI scores decreased from 18.56 ± 5.5 to 14.14 ± 4.7, shifting from "moderate" to "mild" depression by week 12. BHS scores declined from 12.79 ± 2.1 to 10.42 ± 2.2 (both p 0.001), indicating significant but more limited improvement in hopelessness. Subgroup analyses revealed greater psychological recovery in males, married individuals, actively working participants, and those with higher socioeconomic status. Cataract surgery substantially improves both visual function and psychological well-being. Enhancements in visual acuity and NEI VFQ-25 scores parallel significant reductions in depressive symptoms and modest, yet meaningful, declines in hopelessness. Sociodemographic factors influence recovery patterns, underscoring the importance of individualized patient counselling. Cataract surgery should be recognised not only as a visual rehabilitation procedure but also as a valuable intervention supporting emotional and mental health in older adults.

Background: Color blindness or Color Vision Deficiency (CVD) is X-linked recessive disorder characterized by a decreased ability to perceive the difference between colors. Objective: To determine the prevalence rate of color blindness among candidates for new police and military recruits in Kuwait. Methods: A cross-sectional descriptive review of the medical records of 10,000 young male adults (Kuwait has only males in their uniformed officials) who were screened and examined for police and military service between December 2021 and August 2022 was conducted. Ishihara color test plates were used to diagnose color blindness among participants. The findings were divided into two groups. Data were tabulated, and statistically analyzed. The prevalence of color blindness among the new candidates was determined. Results: A total of 10,000 young male adults (As no Uniformed Female is allowed in Kuwait Army) were examined. Among the studied sample, 370(3.7%) out of 10000 were unfit for defense service due to color blindness, with a mean age of 21.7±.39 SD years (range 17-26 years). The prevalence of blindness was found to be 3.7% (2.5-4.9). Conclusion: The prevalence of color blindness among male young recruits was almost the same compared with other studies in neighboring countries and around the world. JAFMC Bangladesh, Vol 21, No 2 (December) 2025:26-28

Impact of colour vision deficiency on bladder and colorectal cancer survival